The use of animal models of weight loss surgery to explore the physiological regulation of energy balance and metabolic function has increased dramatically during the past five years. Because of their powerful physiological effects, these bariatric surgical procedures provide a particularly valuable window on the physiological regulation of body weight, appetitive behavior, energy utilization, glucose homeostasis, lipid metabolism and other related regulatory processes. Small animal models of these operations have been shown to replicate closely their human counterparts. Because of the ease of physiological, pharmacological and genetic manipulation of these animals, these models are highly useful tools. Indeed, many new animals models have recently been developed, and an increasing number of investigators are using these models for a wide variety of studies. Three of the six NIH-sponsored Mouse Metabolic Phenotyping Centers have recently established Bariatric Surgery Animal Cores, and the NIDDK-sponsored Small Animal Metabolic Surgery (SAMS) Core Resource was established in 2009 to facilitate the dissemination of these models to the broader scientific community. As a result of these MMPC and SAMS Core efforts, there has been strong interest in having a workshop on the use and preparation of these models. The overall goals of the proposed workshop program are (1) to increase awareness of these valuable models, (2) to share the results of recent investigations using these models, (3) to share best practices in their preparation and use, and (4) to facilitate their dissemination and use by the broader scientific community. This proposal requests support for this conference, entitled "Animal Models Workshop: The Physiology of Weight Loss Surgery," to be held in Boston, MA on April 3-5, 2011. This second Animal Models Workshop mirrors the organization of the first such workshop, held at this site in 2006. The workshop will include a two-and-one-half day scientific program, followed by a half-day series of live demonstrations of bariatric surgical procedures in rats and mice. The scientific program will include reports from investigators who use these animal models extensively. It will include presentations devoted to the anatomy of the various surgical procedures and their comparative clinical and metabolic outcomes, including their effects on food intake, food preference, appetitive behavior, energy expenditure, physical activity, gastrointestinal function, and glucose and lipid homeostasis. The program will also highlight studies of the physiological and molecular mechanisms underlying these effects, including the role of gut hormones, autonomic neural signaling, central nervous system pathways, portal and hepatic responses, insulin signaling, pancreatic islet cell function, intestinal microbiota, innate and adaptive immune signaling, white adipocyte, brown adipocyte and myocyte responses, genetic determinants of response, and systems biological effects using gene expression, protein and metabolic profiling. The workshop will also include several talks by leading investigators whose focus is on related areas of physiology and whose work may benefit from the knowledge and resources provided by the study of bariatric surgery in patients and animals. Despite their high value, many of these animal models are difficult to establish and used actively by only a limited number of investigators, To facilitate broader use of these models by investigators in multiple disciplines and promote standardization of technique wherever possible, the program will also include live demonstrations of the most commonly rat and mouse models, including Roux-en-Y gastric bypass, vertical sleeve gastrectomy, placement of the endoluminal sleeve device and ileal interposition. PUBLIC HEALTH RELEVANCE: The use of animal models of bariatric surgery to explore the physiological regulation of energy balance and metabolic function has increased dramatically during the past five years. The second Animal Models Workshop: Physiology of Weight Loss Surgery, to be held in Boston, MA on April 3-5, 2011, aims to bring together leading investigators working in this area, including several who use these animal models extensively and others whose focus is on related areas of physiology and whose work may benefit from the knowledge and resources provided by the study of bariatric surgery in patients and animals. The workshop will include a two- and-one-half day scientific program, followed by a half-day series of live demonstrations of Roux-en-Y gastric bypass and other bariatric procedures in rat and mouse models.